In recent years, in the field of structural design, design verification is performed using structural analysis. Particularly, the contact analysis is included in the design verification for an apparatus that is assembled using plural components, and in the contact analysis, contact conditions are set for several thousand locations.
The contact analysis simulates, on a computer, the compositive changes in shape, which occur due to friction in coupling portions of components or due to contact between components. Therefore, in the contact analysis, in case where two components, A and B, collide as schematically illustrated on the left side of FIG. 1, it is not possible to adequately simulate the change in shape of the components due to the collision, if the components slip through each other as schematically illustrated at the top on the right side in FIG. 1. Consequently, as schematically illustrated at the bottom on the right side in FIG. 1, in order to be able to simulate the change in shape due to the collision between the bottom surface of component A and the top surface of component B, the coefficient of friction and other contact conditions are preset for this kind of surface pair.
Such contact conditions may be set beforehand by manually estimating the analysis results based on the visual inspection of the user, or may be set by setting the distance between surfaces as a search condition, and then automatically extracting the surface pairs within the preset distance. However, in the case of using just the distance between surfaces as a search condition, there are problems in that when the preset distance is set to a short distance, it is not possible to extract the actual surface pair between contacting components, and when the preset distance is set to a long distance, the number of surface pairs becomes extremely great, and the computation time becomes very long. Therefore, finally, after human confirmation, the contact conditions are set.
Moreover, when a design is changed and components are exchanged, the contact analysis is performed by setting contact conditions again. Conventionally, as schematically illustrated in FIG. 2A, contact conditions are set for the surface pair of the bottom surface (hatched surface) of component A and the top surface (hatched surface) of component B, however, when the component A is eliminated, only the component B remains as schematically illustrated in FIG. 2B, and the contact conditions are also eliminated. Therefore, as schematically illustrated in FIG. 2C, contact conditions are set again for the surface pair that includes the bottom surface of component C and the top surface of the component B.
In the design stage, design changes are performed repeatedly, however, even though almost the same components are exchanged, the contact conditions are repeatedly reset, so setting the contact conditions takes much time.